Project-level metadata are shared across all the variables available for a project and typically come from the particular data source. For example, for flight data in netcdf the project metadata come from the netcdf global attributes. In cases where there are multiple data sources, such as multiple flight files or a mix of SQL databases and netcdf files, there is no meaningful way to select a single set of project metadata. Rather than try to assimilate or merge metadata from multiple data sources, keep metadata specific to the datasource and make it browseable in a tree, or display it in a table. The GUI must always associate metadata with its data source. This may seem obvious in this context, but it differs from the past handling of project metadata in original RAF display applications like ncplot and WINDS.